A FarmVille-like game that uses ultra-cute Smurf characters has become the highest grossing game in the Apple App Store, but controversy has arisen over its in-game app charges.

Smurfs' Village is free to download, with the developer making its money from in-store purchases. The app has earned four stars in the App Store, with the large majority of comments on the game positive, delighted with the addictive village-building gameplay combined with Smurf cuteness.

But there have been complaints over the way you buy Smurfberries, an in-game currency that allows you to grow your village more quickly. First flagged up by Pocket Gamer, Apple iOS keeps you logged in to your app store account for 15 minutes after you have inputted your password. This means that if you've given a child the game to play with after you've just bought an app or updated one, they can easily buy Smurfberries with a couple of presses.

And these are phenomenally expensive, with £2.99 the lowest amount you can spend. That's more than the price of many apps. But astonishingly, you have options to spend even more than that, with a bushel of Smurfberries costing £6.99, a barrel £17.99, and a wheelbarrow of Smurfberries costing a wallet-smashing £34.99!

David Smout wrote as a comment on the Smurfs' Village iTunes page, "We installed this for my son and sat with him playing it. It wasn't clear that the purchases were not in-game fantasy credit but were actually charged to my iTunes account.

"At no point was my password asked for. Even updating apps requires my password and I deliberately don't have 1-click purchasing enabled. Since been uninstalled."

We downloaded Smurfs' Village for the iPhone, and it was very easy to enter the Smurfberry shop and spend £35 with just a click of the button, without any password-prompting.
This game is marketed at children, and you can see many of them chasing these berries in their hunger to grow their village as big as possible. If you are concerned, there is a way you can stop in-app purchases in the restriction menu of settings.

"Capcom has been in the videogame business for more than 25 years, so the last thing we want is to be misperceived as taking advantage of children," a company spokesman said. "We find consumer complaints of children inadvertently purchasing in-app content lamentable.

"Unfortunately, once a customer downloads an app their account remains active for 15 minutes. During this time it's possible to download in-app content without re-entering the password. This is not unique to our app, this is a function of iOS and we have no control over it. Since this has come to our attention we've added clarifications and warnings to the App Store description. If parents think their child may have purchased in-App content by accident, they can request a refund from Apple."